Commit 59842c54 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Daniel Borkmann
Browse files

libbpf: Ensure libbpf always opens files with O_CLOEXEC 



Make sure that libbpf code always gets FD with O_CLOEXEC flag set,
regardless if file is open through open() or fopen(). For the latter
this means to add "e" to mode string, which is supported since pretty
ancient glibc v2.7.

Also drop the outdated TODO comment in usdt.c, which was already completed.

Suggested-by: default avatarLennart Poettering <lennart@poettering.net>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230525221311.2136408-1-andrii@kernel.org
parent 321a64b3

tools/lib/bpf/btf.c

+1 −1
Original line number Diff line number Diff line
@@ -1064,7 +1064,7 @@ static struct btf *btf_parse_raw(const char *path, struct btf *base_btf) 
	int err = 0;

	long sz;



	f = fopen(path, "rb");

	f = fopen(path, "rbe");

	if (!f) {

		err = -errno;

		goto err_out;

tools/lib/bpf/libbpf.c

+3 −3
Original line number Diff line number Diff line
@@ -4351,7 +4351,7 @@ static int bpf_get_map_info_from_fdinfo(int fd, struct bpf_map_info *info) 
	snprintf(file, sizeof(file), "/proc/%d/fdinfo/%d", getpid(), fd);

	memset(info, 0, sizeof(*info));



	fp = fopen(file, "r");

	fp = fopen(file, "re");

	if (!fp) {

		err = -errno;

		pr_warn("failed to open %s: %d. No procfs support?\n", file,
@@ -7455,7 +7455,7 @@ int libbpf_kallsyms_parse(kallsyms_cb_t cb, void *ctx) 
	int ret, err = 0;

	FILE *f;



	f = fopen("/proc/kallsyms", "r");

	f = fopen("/proc/kallsyms", "re");

	if (!f) {

		err = -errno;

		pr_warn("failed to open /proc/kallsyms: %d\n", err);
@@ -10075,7 +10075,7 @@ static int parse_uint_from_file(const char *file, const char *fmt) 
	int err, ret;

	FILE *f;



	f = fopen(file, "r");

	f = fopen(file, "re");

	if (!f) {

		err = -errno;

		pr_debug("failed to open '%s': %s\n", file,

tools/lib/bpf/libbpf_probes.c

+1 −1
Original line number Diff line number Diff line
@@ -38,7 +38,7 @@ static __u32 get_ubuntu_kernel_version(void) 
	if (faccessat(AT_FDCWD, ubuntu_kver_file, R_OK, AT_EACCESS) != 0)

		return 0;



	f = fopen(ubuntu_kver_file, "r");

	f = fopen(ubuntu_kver_file, "re");

	if (!f)

		return 0;

tools/lib/bpf/usdt.c

+2 −3
Original line number Diff line number Diff line
@@ -466,7 +466,7 @@ static int parse_vma_segs(int pid, const char *lib_path, struct elf_seg **segs, 


proceed:

	sprintf(line, "/proc/%d/maps", pid);

	f = fopen(line, "r");

	f = fopen(line, "re");

	if (!f) {

		err = -errno;

		pr_warn("usdt: failed to open '%s' to get base addr of '%s': %d\n",
@@ -954,8 +954,7 @@ struct bpf_link *usdt_manager_attach_usdt(struct usdt_manager *man, const struct 
	spec_map_fd = bpf_map__fd(man->specs_map);

	ip_map_fd = bpf_map__fd(man->ip_to_spec_id_map);



	/* TODO: perform path resolution similar to uprobe's */

	fd = open(path, O_RDONLY);

	fd = open(path, O_RDONLY | O_CLOEXEC);

	if (fd < 0) {

		err = -errno;

		pr_warn("usdt: failed to open ELF binary '%s': %d\n", path, err);